REY apps can be built locally in a development environment before being published on the testnet environment. This section describes the differences between both.

When using rey-cli, you can easily switch from one environment to another by changing the first argument (dev or test). You can also set a custom environment if you’re running your own node, and specify your RPC URL and contract addresses.

Before making our app available to everyone, we’ll be building it inside our own development environment. To achieve this, the simplest way is to run your own private node with REY’s smart contract and registry already deployed. There’s a Docker image that provides a geth instance that has both smart contracts already deployed and ready to use at the following addresses: